// verifast_options{disable_overflow_check target:ILP32}

int SIZE = 50000001;
int __VERIFIER_nondet_int();//@ requires true; 
//@ ensures true;

extern void abort(void);//@ requires true; 
//@ ensures true;

extern void __assert_fail(const char *, const char *, unsigned int, const char *) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__noreturn__));
void reach_error() //@ requires false; 
//@ ensures true;
{ __assert_fail("0", "loopv2.c", 5, "reach_error"); }
extern void abort(void);
void assume_abort_if_not(int cond) //@ requires true; 
//@ ensures true;
{
  if(!cond) {abort();}
}
void __VERIFIER_assert(int cond) //@ requires integer(&SIZE, ?veri_req_SIZE) &*& (1 <= cond); 
//@ ensures integer(&SIZE, ?veri_ens_SIZE) &*& ((veri_req_SIZE == veri_ens_SIZE) && (1 <= cond));
{
  if (!(cond)) {
    ERROR: {reach_error();abort();}
  }
  return;
}
int __VERIFIER_nondet_int();
int main() //@ requires module(loopv2__verifast_instrumented_modified, true); 
//@ ensures junk();
{
  int n,i,j,k;
//@ invariant integer(&SIZE, ?veri_req_SIZE) &*& true;
  n = __VERIFIER_nondet_int();
  if (!(n <= SIZE)) return 0;
  i = 0; j=0;
  while(i<n)//@ invariant integer(&SIZE, ?veri_inv_SIZE) &*& (0 == (i % 2));
{ 

    i = i + 4;
    j = i +2;    
  }
  k =i;
  while( (j%2) == 0)//@ invariant integer(&SIZE, ?veri_inv_SIZE) &*& ((k % 2) == 0);
{
   j-=4;
   k -=4; 
  }
  __VERIFIER_assert( (k%2) == 0 );
  return 0;
}